This invention relates to a radiographic opaque and conductive striped medical tube such as catheters, cannulae and other similar tubes which are introduced into the body cavity during medical procedures and in particular to such a tube which can be accurately located through radiographic observation and which eliminate possible hazardous electrostatic charge conditions.
Catheters and like cylindrical tubes for introduction to the body cavity are presently of rubber, vinyl and other thermoplastic materials. Extruded plastic materials are widely employed because of the economies of production which permit construction of disposable tubes. Such tubes have been constructed with an X-ray opaque stripe extending throughout the length of the tube. By directing a beam of X-rays through the body of the patient in the neighborhood of the inserted medical tube, the relative position of the catheter and the living tissue will appear on a fluoroscope or X-ray film. The stripe may include any suitable X-ray opaque pigment such as one of the bismuth salts. A highly satisfactory X-ray opaque medical tube is more fully disclosed in U.S. Pat. No. 3,749,134 wherein the tube is formed of suitable thermoplastic resin including a particular diol of a tetrabromophthalic anhydride to make the tube radiographic. In addition to location of the tube within the body cavity, care must often be taken such as under surgical procedures to avoid creation of electrostatic discharge conditions. Thus, plastic materials which are widely employed in surgical tubes are known to acquire electrostatic charges when brought in frictional contact with other bodies such as certain fabrics. This may create a highly hazardous condition in the presence of explosive gases such as will normally be encountered in surgical areas as a result of the use of various anesthetizing gases. Recommended safe-practice standards have been established requiring the use of electrically conductive elements within the tube to permit grounding and discharge of any electrostatic charge. It has even been suggested that the tube be formed with a suitable conductive strip formed by conductive particles dispersed throughout the strip portion of the tube. When using a pigment, consideration must be given to the strength characteristics of the tube and the like. Further, as the particles are completely of different characteristics and function in completely different manners, individual and separate stripes have been employed. The formation of a tube with the several different stripes and characteristics presents significant practical difficulties in the construction of a tube and generally the tubes have heretofor been constructed with either one or the other of the individual and separate functional portions.